nes-proj/cpu/x86/init/legacy_pc/irq.c

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/*
* Copyright (C) 2015, Intel Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "drivers/legacy_pc/pic.h"
#include "interrupt.h"
#include "irq.h"
#define IRQ7_INT PIC_INT(7)
static void
spurious_irq7_handler(void)
{
/*
* NOTE: Originally IRQ7 was used for the parallel port interrupts. Nowadays,
* though, it is only used if some other IRQ (i.e.: a PCIx interrupt) is
* mapped to it. In this case we will have to check the PIC ISR register in
* order to confirm this was a real interrupt.
*
* In case of a spurious interrupt, we should NEVER send an EOI here so the PIC
* doesn't trigger the next queued interrupt.
*/
}
/*---------------------------------------------------------------------------*/
void
irq_init(void)
{
pic_init();
/* Set a 'fake' handler for the Spurious IRQ7 interrupts.
* Refer to http://wiki.osdev.org/PIC .
*/
SET_INTERRUPT_HANDLER(IRQ7_INT, 0, spurious_irq7_handler);
}